"All in good time, love." Sirius grinned, pressing a laughing kiss against James' inner thigh.
Sirius went longer than he'd planned, longer than he thought he'd had in him in all honesty, but the way James moved with him, the way his hips rocked for just his fingers, Sirius couldn't help himself but to draw it out just a bit longer.
It was only when James warned him that he was close that Sirius stopped the slow steady thrusting of his fingers, pulling them free. He wanted James to come, but the way James told him to stop - Sirius could hear what he wanted in it. And he was changing their position again, letting James' legs wrap around his waist and once he had the angle right he pushed himself into James in one long slow thrust until his hips settled against James'.
"Oh god." He gasped, pressing his forehead against James' shoulder. "You're always so perfect like this." His voice was pitched low as he raised his head, lips dragging their way as he went until he could reach James' lips again.